Self-assembled materials with an ordered hydrophilic bilayer for high performance inverted Perovskite solar cells.

While self-assembled material based inverted perovskite solar cells have surpassed power conversion efficiencies of 26%, enhancing their performance in large-area configurations remains a significant challenge. In this work, we report a self-assembled material based hole-selective layer 4-(7H-dibenzo[c,g]carbazol-7-yl)phenyl)phosphonic acid, with a π-expanded conjugation. The enhanced intermolecular π-π interactions facilitate the self-assembly of 4-(7H-dibenzo[c,g]carbazol-7-yl)phenyl)phosphonic acid molecules to form an ordered bilayer with a hydrophilic surface, which passivates the buried perovskite interface defect and enables high-quality and large-area perovskite preparation, while simultaneously enhancing interfacial charge extraction and transport.

Vertically Oriented Quasi-2D Perovskite Grown In-Situ by Carbonyl Array-Synergized Crystallization for Direct X-Ray Detectors.

Quasi-2D perovskite quantum wells are increasingly recognized as promising candidates for direct-conversion X-ray detection. However, the fabrication of oriented and uniformly thick quasi-2D perovskite films, crucial for effective high-energy X-ray detection, is hindered by the inherent challenges of preferential crystallization at the gas-liquid interface, resulting in poor film quality. In addressing this limitation, a carbonyl array-synergized crystallization (CSC) strategy is employed for the fabrication of thick films of a quasi-2D Ruddlesden-Popper (RP) phase perovskite, specifically PEAMAPbI.

Ammonia Electrosynthesis from Nitrate Using a Ruthenium-Copper Cocatalyst System: A Full Concentration Range Study.

Electrochemical synthesis of ammonia via the nitrate reduction reaction (NO3RR) has been intensively researched as an alternative to the traditional Haber-Bosch process. Most research focuses on the low concentration range representative of the nitrate level in wastewater, leaving the high concentration range, which exists in nuclear and fertilizer wastes, unexplored. The use of a concentrated electrolyte (≥1 M) for higher rate production is hampered by poor hydrogen transfer kinetics.

Significant Enhancement of Circular Polarization in Light Emission through Controlling Helical Pitches of Semiconductor Nanohelices.

Circularly polarized light emission (CPLE) can be potentially applied to three-dimensional displays, information storage, and biometry. However, these applications are practically limited by a low purity of circular polarization, i.e.

Application of Natural Molecules in Efficient and Stable Perovskite Solar Cells.

Perovskite solar cells (PSCs), one of the most promising photovoltaic technologies, have been widely studied due to their high power conversion efficiency (PCE), low cost, and solution processability. The architecture of PSCs determines that high PCE and stability are highly dependent on each layer and the related interface, where nonradiative recombination occurs. Conventional synthetic chemical materials as modifiers have disadvantages of being toxic and costly.

Metal-Induced Planar Chirality of Soft-Bridged Binuclear Platinum(II) Complexes: 100 % Phosphorescence Quantum Yields, Chiral Self-Sorting, and Circularly Polarized Luminescence.

Pt complexes have attracted a great deal of interest due to their rich phosphorescent properties. However, these square-planar Pt complexes are far more likely to encounter the problems of lack of metal-induced chirality and emission "aggregation-caused quenching". Herein, soft-bridged binuclear Pt complexes bearing metal-induced planar chirality were synthesized and characterized.

Precise modulation strategies of 2D/3D perovskite heterojunctions in efficient and stable solar cells.

2D/3D perovskite heterojunctions exhibit promising prospects in the improvement of efficiency and stability of perovskite solar cells (PSCs). However, many challenges remain in the development of high-quality 2D/3D heterojunctions, such as a reliable pathway to control the perovskite phase and generally poor performance in inverted (p-i-n) devices, which limit their commercialization. Fortunately, many excellent works have proposed lots of strategies to solve these challenges, which have triggered a new wave of research on 2D/3D perovskite heterojunctions in recent years.

1-Adamantanamine Hydrochloride Resists Environmental Corrosion to Obtain Highly Efficient and Stable Perovskite Solar Cells.

Passivating the defective surface of perovskite film is a promising strategy to improve the stability and efficiency of perovskite solar cells (PSCs). Herein, 1-adamantanamine hydrochloride (ATH) is introduced to the upper surface of the perovskite film to heal the defects of the perovskite surface. The best-performance ATH-modified device has a higher efficiency (23.

Gold(I) Multi-Resonance Thermally Activated Delayed Fluorescent Emitters for Highly Efficient Ultrapure-Green Organic Light-Emitting Diodes.

Acceleration of singlet-triplet intersystem crossings (ISC) is instrumental in bolstering triplet exciton harvesting of multi-resonance thermally activated delayed fluorescent (MR-TADF) emitters. This work describes a simple gold(I) coordination strategy to enhance the spin-orbit coupling of green and blue BN(O)-based MR-TADF emitters, which results in a notable increase in rate constants of the spectroscopically observed ISC process to 3×10  s with nearly unitary ISC quantum yields. Accordingly, the resultant thermally-stable Au emitters attained large values of delayed fluorescence radiative rate constant up to 1.

Room-Temperature Phosphorescence of Pure Axially Chiral Bicarbazoles.

Ultralong room-temperature phosphorescence (RTP) is greatly important in a series of applications, but obtaining RTP from metal-free organic materials is still an enormous challenge due to the spin-forbidden nature of triplet excitons. Because of its electron-rich nature and easy derivatization, carbazole (Cz) is widely used to build organic RTP and thermally activated delayed fluorescence (TADF) materials. However, Liu et al.

Synergy Effect of a π-Conjugated Ionic Compound: Dual Interfacial Energy Level Regulation and Passivation to Promote V and Stability of Planar Perovskite Solar Cells.

Defects and energy offsets at the bulk and heterojunction interfaces of perovskite are detrimental to the efficiency and stability of perovskite solar cells (PSCs). Herein, we designed an amphiphilic π-conjugated ionic compound (QAPyBF ), implementing simultaneous defects passivation and interface energy level alignments. The p-type conjugated cations passivated the surface trap states and optimized energy alignment at the perovskite/hole transport layer.

Highly Phosphorescent Planar Chirality by Bridging Two Square-Planar Platinum(II) Complexes: Chirality Induction and Circularly Polarized Luminescence.

Chiral organometallic complexes have demonstrated many potential and practical applications. However, building metal-induced chirality for square-planar complexes still remains a big challenge, because their 2D planar molecular structures are usually superimposable on their mirror images. Herein, we report a straightforward and efficient way to achieve a novel kind of planar chirality by constructing 3D double-layer molecular structures.

Axially Chiral Bis-Cycloplatinated Binaphthalenes and Octahydro-Binaphthalenes for Efficient Circularly Polarized Phosphorescence in Solution-Processed Organic Light-Emitting Diodes.

A new series of axially chiral binuclear Pt(II) complexes with bridging ligands of binaphthalenes and octahydro-binaphthalenes and auxiliary ligands of β-diketones were designed and prepared. These complexes, identified by spectral and electrochemical methods and single-crystal X-ray diffraction, emit an orange-red phosphorescence with a quantum yield up to 21% and 70% in solution and solid, respectively, due to the effect of steric hindrance from bridging ligands and the 2,3-position extension of chiral axis planes. They can be used as emitters in solution-processed organic light-emitting diodes to achieve luminance efficiency, asymmetry factor, and external quantum efficiency up to 5.

Fabrication of copper phthalocyanine/reduced graphene oxide nanocomposites for efficient photocatalytic reduction of hexavalent chromium.

Copper(II) phthalocyanine (CuPc) and non-peripheral octamethyl-substituted copper(II) phthalocyanine (N-CuMePc) were combined with reduced graphene oxide (rGO) via a precipitation method to form CuPc/rGO and N-CuMePc/rGO nanocomposites, respectively. CuPc nanorods are distributed on rGO, and N-CuMePc exists as nanorods and nanoparticles on rGO. The Cr(VI) removal ratio of N-CuMePc/rGO exposed in simulated sunlight is 99.

Dual Defect-Passivation Using Phthalocyanine for Enhanced Efficiency and Stability of Perovskite Solar Cells.

Semiconducting molecules have been employed to passivate traps extant in the perovskite film for enhancement of perovskite solar cells (PSCs) efficiency and stability. A molecular design strategy to passivate the defects both on the surface and interior of the CH NH PbI perovskite layer, using two phthalocyanine (Pc) molecules (NP-SC -ZnPc and NP-SC -TiOPc) is demonstrated. The presence of lone electron pairs on S, N, and O atoms of the Pc molecular structures provides the opportunity for Lewis acid-base interactions with under-coordinated Pb sites, leading to efficient defect passivation of the perovskite layer.

Efficient degradation of organic dye using Ni-MOF derived NiCo-LDH as peroxymonosulfate activator.

Nickel-based metal-organic framework (Ni-MOF) was employed as a sacrificial template for the preparation of nickel-cobalt layered double hydroxide (NiCo-LDH) under different hydrolysis time. The template etching rate varied at different hydrolysis time, resulting in variations of the structural and morphology of NiCo-LDHs. The NiCo-LDH/10 sample showed a large specific surface area and the well-oriented larger dimension of thinner sheets due to the sufficient in-situ etching of the Ni-MOF template.

In situ synthesis of N-CoMePc/rGO nanocomposite with enhanced photocatalytic activity and stability in Cr(VI) reduction.

Graphene-based composites are widely used in the photocatalytic treatment of heavy-metal ions or dyes. In this study, we developed a facile in situ precipitation method for preparing a non-peripheral octamethyl-substituted cobalt(II)phthalocyanine (N-CoMePc)/reduced graphene oxide (rGO) nanocomposite as an efficient photocatalyst. The physical and chemical properties of the nanocomposite were investigated by scanning electron microscopy, transmission electron microscopy, x-ray diffraction, and ultraviolet-visible, ultraviolet photoelectron, Fourier-transform infrared, Raman, and x-ray photoelectron spectroscopies.

Molecular Design Strategy in Developing Titanyl Phthalocyanines as Dopant-Free Hole-Transporting Materials for Perovskite Solar Cells: Peripheral or Nonperipheral Substituents?

We demonstrate a molecular design strategy to enhance the efficiency of phthalocyanine (Pc)-based hole-transporting materials (HTMs) in perovskite solar cells (PSCs). Herein, two titanyl phthalocyanine (TiOPc) derivatives are designed and applied as dopant-free HTMs in planar n-i-p-structured PSCs. The newly developed TiOPc compounds possess eight -hexylthio groups attached to either peripheral (-SC-TiOPc) or nonperipheral (-SC-TiOPc) positions of the Pc ring.

Soluble hexamethyl-substituted subphthalocyanine as a dopant-free hole transport material for planar perovskite solar cells.

Boron subphthalocyanine (SubPc) has special physical and chemical properties, originating from its non-centrosymmetric, near-planar taper structure and large conjugated system; it can act as an alternative to the small molecule hole-transporting material 2,2',7,7'-tetrakis-(,-di--methoxyphenylamine)-9,9'-spirobifluorene in perovskite solar cells (PSCs). To achieve a higher solubility in common organic solvents and a more suitable highest occupied molecular orbital energy level that aligns with the valence band of the perovskite material, a SubPc molecule with a hexamethyl substitution at its peripheral position (Me-SubPc) was successfully designed and synthesized in a one-step method. Completely solution processed PSCs were fabricated with only a small hysteresis, a power conversion efficiency of 6.

Ultrasonic-Assisted Wet Chemistry Synthesis of Ultrafine SnO Nanoparticles for the Electron-Transport Layer in Perovskite Solar Cells.

SnO was recently employed as an efficient electron-transport layer (ETL) in perovskite solar cells (PSCs) and high power conversion efficiencies (PCEs) have been reported. However, it is still challenging to fabricate SnO thin films through facile solution-based synthesis at low temperature (<150 °C) to be compatible with the large scale module fabrication, especially for flexible devices. Here, we report a low temperature solution-based method for preparation of SnO nanoparticles.

Improvement of the photovoltaic parameters of perovskite solar cells using a reduced-graphene-oxide-modified titania layer and soluble copper phthalocyanine as a hole transporter.

Functional perovskite solar cells can be made by using a simple, inexpensive and stable soluble tetra-n-butyl-substituted copper phthalocyanine (CuBuPc) as a hole transporter. In the present study, TiO/reduced graphene oxide (T/RGO) hybrids were synthesized via an in situ solvothermal process and used as electron acceptor/transport mediators in mesoscopic perovskite solar cells based on soluble CuBuPc as a hole transporter and on graphene oxide (GO) as a buffer layer. The impact of the RGO content on the optoelectronic properties of T/RGO hybrids and on the solar cell performance was studied, suggesting improved electron transport characteristics and photovoltaic parameters.

Dopant-Free Hole-Transport Materials Based on Methoxytriphenylamine-Substituted Indacenodithienothiophene for Solution-Processed Perovskite Solar Cells.

Solution-processed hole transporting materials (HTMs) that are dopant-free show promise for use in low-cost, high-performance perovskite solar cells (PSCs). The highest-efficiency PSCs use organic HTMs, many of which have low mobilities and therefore require doping, which lowers the device stability. Additionally, these materials are not easily scaled because they often require complicated synthesis.

Self-aligned, full solution process polymer field-effect transistor on flexible substrates.

Conventional techniques to form selective surface energy regions on rigid inorganic substrates are not suitable for polymer interfaces due to sensitive and soft limitation of intrinsic polymer properties. Therefore, there is a strong demand for finding a novel and compatible method for polymeric surface energy modification. Here, by employing the confined photo-catalytic oxidation method, we successfully demonstrate full polymer filed-effect transistors fabricated through four-step spin-coating process on a flexible polymer substrate.